Lol what? Their system makes more sense

To make a circular mask in gimp, use the circle select tool, then fill your selection.

This, I’ve never understood the learned helplessness of some people. The 12,000 employee international company I work for doesn’t pay for any Adobe products. You can just use literally any other product or open source alternative, I promise you there are multiple good ones with extremely well supported professional workflows used by millions of people every day, for every conceivable Adobe product. You can learn a new workflow I believe in you, it will take like three months to get used to.